The use of plant exudates and gels from the Aloe vera plant is described extensively in the medical, folk and patent literature. Over the centuries, plants have served as the major source of medicines for mankinds treatment of disease. In fact it has only been in relatively recent times that synthesis and drug design have served to provide the drugs used in therapeutics. Never-the-less plants still have a part in folk and propriety medicine. These uses, in many instances, may be at variance with the use predicated by the type of activity afforded by the major phytoconstituent present. A large group of plants contain anthraquinones and anthraquinone-glycosides and because of this have been, and still are, used as laxatives.
Aloe vera is a prime example. It has been used for centuries as a source of Aloin and for its use as a laxative. However the leaves have also served as a source of gel which has had a wide and varied use. Aloe vera gel is the yellowish, viscous, watery gel secreted from the leaves of the Aloe vera plant and the gel has been reported to be used by primitive civilizations for the treatment of burns, kidney and bladder infections, prostatitis, dysentery and following periodontal surgery; R. Henry, An Updated Review of Aloe Vera, Cosmetics & Toiletries, Vol. 94, pp. 42-50 (1979). Topical wounds and burns are treated with a gel containing a salt of naturally occurring polyuronide derived from aloe in U.S. Pat. No. 3,013,466 to Farkas while a polysaccharide product derived from the juice of the aloe plant used for the treatment of wounds is described in Farkas' later patent 3,362,951. Aloe vera gel is described for the treatment of wounds, blisters and other lesions in U.S. Pat. Nos. 3,892,853 to Cobble and 3,360,511 to Maret. The effectiveness of Aloe vera in the treatment of thermal and radiation burns, wounds, chapped and dry skin, peptic ulcers, chronic ulcers and dermatoses is reported as are folk uses of Aloe vera for the treatment of venerial sores, boils, hemorrhoids and a host of other ailments; see A. Y. Leung, Aloe Vera in Cosmetics, D&CI, pp.34 (June 1977) and G. Gjerstad et al, Current Status of Aloe as a Cure-All, American Journal of Pharmacy, pp. 59-64 (March-April, 1968). However most other anthraquinone containing plants, except for those such as madder root (Rubia tinctorum) which are used as dyes, have been used for their laxative abilities.